The lane keeping assist function integrated in the vehicle or the LKA system (Lane Keeping Assist System), in short LKAS, may assist the driver in the lateral guidance of the vehicle. In the center guidance mode of the lane keeping assist system, the LKAS function primarily steers and keeps the vehicle in the center of the lane. In terms of control technology, the driver does not even have to steer. For safety reasons, however, the driver must keep the hands on the steering wheel. In addition, autonomous driving pursuant to the Vienna Convention is presently not yet legally permitted in most countries of the world.
Therefore, a so-called hands-off detection is presently carried out in vehicles which include the LKAS function (in particular, including center guidance mode), in which it is checked whether or not the driver has the hands on the steering wheel. If the driver is not holding the steering wheel, a warning is issued and the steering assist is switched off. For the hands-off detection, the comparison of the measured steering wheel torque with a threshold is related art. If the measured steering wheel torque is too low for a long period of time, for example, more than 15 seconds, hands-off is recognized.